why we need social media?

[Seng]

[?]

We don't 'need' it.

It's a consumer product just like the cell phone or computer you used to connect to the internet and post this question with.

These items are not 'needed' for the survival of human beings (but people like them, hence most everyone seems to have a computer and/or cell phone and internet access.)

Some people who have computers with internet access choose not to use social media sites. That's the key point. It's a *choice*.